Written By Gopal Krishna on Saturday, September 20, 2008 | 9:01 AM

ORISSA FLOOD DISASTER COULD HAVE BEEN AVOIDED: WRONG OPERATION OF HIRAKUD DAM RESPONSIBLE

The wrong operation of Hirakud Dam is majorly responsible for the current flood disaster in Mahanadi basin in Orissa. The Hirakud dam operators have kept the water level way above the rule curve recommended for the dam in 1988, ever since Aug 1, 2008, when the rule curve for current year comes into operation. Had the dam operated in a way to keep the level below the recommended level, the current flood disaster could have been avoided.

The water flow in Mahanadi basin at Mundali barrage is 14.6 lakh cusecs (cubic feet per second), way above the safe limit of 10 lakh cusec, as recommended by the August 2007 report of "the High Level Committee to Study Various Aspects of Water Usage for Hirakud Reservoir", appointed by the Government of Orissa. Out of the 14.6 lakh cusecs flowing in Mahanadi, over 4.62 lakh cusecs is released by Hirakud dam. If Hirakud Dam had not released the water when the downstream areas were experiencing heavy rainfall, the amount the flow at Mundali barrage would have remained within the safe limit of 10 lakh cusecs as recommended by the High Level Hirakud Committee (HLHC), and there would have been no flood disaster.

The Hirakud dam operators are forced to release over 4.62 lakh cusecs, because the water level at Hirakud dam has already reached the Full Reservoir Level of 630 feet on Sept 18, 2008, which should have been reached that level twelve days later on Sept 30, 2008. And the water level at Hirakud has reached the full level so fast because the operators had consistently kept the water level very high, way above the recommended level.

For example, on Aug 1, 2008, the recommended water level at Hirakud dam was 590 feet, but the actual water level on that date was already way high at 607.5 feet. On Aug 13, 2008, the water level was 618.5 feet, against the recommended level of 606 feet. On Sept 10, 2008, the water level was 627 feet, just three feet below the full level, when the recommended level was only 623 feet.

Hirakud dam is one of the few dams of India where flood control cushion has been provided in its storage capacity. The idea is that the flood cushion portion of the storage should not be filled right till the end of the monsoon, which is in the first week of Oct. By filling up the reservoir to full capacity before the end of monsoon, the dam operators have destroyed the flood control role of the Hirakud dam and thus brought an avoidable flood disaster on the people of Orissa. This disaster could have been avoided, had they operated the dam keeping in mind the flood cushion role of the reservoir.

Here it may be added that the Central Water Commission (CWC) of the Government of India has been using completely outdated figures of reservoir capacities. For example, for Hirakud, while the HLHC has said that the live storage capacity of Hirakud in 2007 was down to 4.647 Billion Cubic Meters (BCM) (down from 5.818 BCM at the time of start up in 1957), CWC's reservoir storage website (http://www.cwc.gov.in/Reservoir_level.htm) says the Hirakud's live storage capacity is 5.378 BCM. This is higher than that given by even CWC's own 1995 study of Hirakud siltation, which said the live capacity by that year had gone down to 4.934 BCM. It is also shocking to note that CWC's flood forecast site first time (during the current phase) mentioned the Mahanadi floods only on September 19, 2008, after the news was already out in the media. What is the value of such forecasts of CWC?

The Orissa government needs to answer to the people of Orissa, why this shocking manmade disaster was allowed to happen and what it would do to ensure that those who are responsible for the wrong operation of the Hirakud dam are held accountable?